Tankless water heater?

[Brian Fein]

real talk because i don't know....

How does a solar water heater work if you want to shower at night?

[pondwater]

real talk because i don't know....

How does a solar water heater work if you want to shower at night?

It's basically a big tank on your roof with solar panels that heats up the water. It doesn't replace the water heater, it's in addition to the water heater. I don't know exactly how it works, but I assume that as you use hot water out of your electric water heater, the water from the solar tank replaces the water you used. And therefore the electric water heater doesn't have to run as much because the inlet water coming from the roof is already hot or warm .

[Brian Fein]

It's basically a big tank on your roof with solar panels that heats up the water. It doesn't replace the water heater, it's in addition to the water heater. I don't know exactly how it works, but I assume that as you use hot water out of your electric water heater, the water from the solar tank replaces the water you used. And therefore the electric water heater doesn't have to run as much because the inlet water coming from the roof is already hot or warm .

thanks, that makes sense.  I knew a guy that had a solar pool heater on his roof, which basically was a huge flat glass thing that the pool pump fed water to the top, the water dripped down the slope of the roof under glass and got heated up by the sun.  then collected at the bottom and pumped into the pool at a hotter temperature.  But no one cares if your pool isn't heated when the sun goes down...

Wasn't sure if it was something like that.

[Dave Gray]

I don't know what I'm talking about.


That said, I believe that there is some kind of solar water heater that is essentially black tubing with water inside that gets hot living on your roof.  Then, as pond says, you still have a traditional water heater but the water getting fed into it is already hot and needs less energy to get to the usage temperature.

[MyGodWearsAHoodie]

There are more than one type of solar water heater. 

In my part of the country the panels don't heat water directly they heat a liquid that has a much lower freezing point and use a heat exchange.

As for taking a shower at "night."  This is not exact just a general overview. 

Note: normal hot water temperature is 115-120F

The systems can heat the liquid to 180F.  Even on a cloudy freezing day. 

The tank is insulated.   

So it works something like this....water is heated to 180F in tank.  If you take a shower at sunset -- the regulator is going to mix in a lot of cold water too cool down to 120F.  But in the morning when you take a shower and the water in the tank has dropped to 170F - the regulator is still going to mix in a lot of cold water to cool it down to 120F (but the mixture will be more hot and less cold than it was at sunset)